The invention relates to a rear axle of a two-track vehicle with three control arms which are connected in an articulated manner to a wheel carrier and extend substantially in the vehicle transverse direction, and a trailing arm which is connected rigidly to the wheel carrier and has sufficient flexibility in the vehicle transverse direction as a result of its structure or its vehicle body-side mounting. A support spring which proportionally supports the vehicle body with respect to a wheel which is mounted rotatably on the wheel carrier and a vibration damper which is connected in parallel in terms of action to the support spring are supported below the wheel center on a cantilever which protrudes from the wheel carrier toward the vehicle center plane. FR 2 914 586 A1 discloses a rear axle having the above features. Furthermore, with respect to prior art, reference is made to JP 62-18309 and EP 0 136 563 B2.
The axle construction shown in EP 0 136 563 B2 is also called a control blade axle, which construction is more favorable with regard to the force conditions in the context of the support of the vehicle body than many other control blade axles which are currently in series production, since both the support (suspension) spring and the vibration damper are supported directly on the wheel carrier in EP 0 136 563 B2. Neither the control arms nor their joints are therefore loaded with the weight of the vehicle body and a functionally favorable rate can be produced in any case for the damper. However, the installation space requirement of this known construction is relatively high, in particular as viewed in the vertical direction, with the result that an improvement is desired not only in this regard, but rather also a favorable rear-axle design which has a high mechanical load capacity is sought in which the wheel is not only driven, but rather can also be steered, at least slightly. FR 2 914 586 A1 which was mentioned in the introduction also cannot offer any suggestion in this respect.
The present invention solves these problems in a vehicle rear axle of a two-track vehicle. As viewed in the driving direction, the support spring is supported in front of the wheel center and below the wheel center on a cantilever which protrudes from the wheel carrier toward the vehicle center plane to such an extent that a drive shaft, which runs as customary in the vehicle transverse direction, is located behind the support spring. By way of a suggested low arrangement, the support spring can be arranged practically completely below a body longitudinal carrier of the vehicle body in conjunction with a compact design of the support spring which arises from a spring rate which can be produced in the order of magnitude from 0.7 to 0.8, resulting from the support on a cantilever which protrudes toward the vehicle center plane. In the case of a passenger car, therefore, an extremely wide and low-lying trunk floor can be produced.
Furthermore, the control arm which is articulated on the wheel carrier above the center point of the driven wheel in the vertical direction is connected to the wheel carrier behind the wheel center as viewed in the driving direction, and the control arm which is articulated on the wheel carrier in front of the wheel center as viewed in the driving direction is connected to the wheel carrier below the wheel center in the vertical direction. A favorably running steering axis for the wheel is described by way of these articulation points, with the result that finally the control arm which is arranged furthest to the rear as viewed in the driving direction is connected by way of its end which faces away from the wheel carrier to a steering actuator for the wheel and, therefore, acts as a toe link.
Furthermore, the vibration damper is also supported on the cantilever—preferably further to the outside than the support spring—and the trailing arm is fastened to the cantilever. In this way, not only a rigid assembly, but rather also a favorable introduction of the additional spring force from the damper can be produced. A receptacle bracket for the (lower) damper bearing is provided, as it were, as a direct extension of the trailing arm, which extension passes through the cantilever, and therefore provides additional reinforcement of this assembly of trailing arm and cantilever or wheel carrier.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.